jackson2.1.4 序列化对象时，为NULL的属性不序列化

下载地址 http://jackson.codehaus.org/

public class User {

	public User() {
	}
	
	public User(int id, String name, Date birthday) {
		super();
		this.id = id;
		this.name = name;
		this.birthday = birthday;
	}

	private int id;
	
	private String name;
	
	private Date birthday;

	public int getId() {
		return id;
	}

	public void setId(int id) {
		this.id = id;
	}

	public String getName() {
		return name;
	}

	public void setName(String name) {
		this.name = name;
	}
        //将该标记放在属性上，如果该属性为NULL则不参与序列化
        //如果放在类上边,那对这个类的全部属性起作用
		//Include.Include.ALWAYS 默认
		//Include.NON_DEFAULT 属性为默认值不序列化
		//Include.NON_EMPTY 属性为 空（“”）  或者为 NULL 都不序列化
		//Include.NON_NULL 属性为NULL 不序列化
	@JsonInclude(Include.NON_NULL)
	public Date getBirthday() {
		return birthday;
	}

	public void setBirthday(Date birthday) {
		this.birthday = birthday;
	}
	
}

//测试方法
ObjectMapper mapper = new ObjectMapper();
User user = new User(1,"jack",null);
String outJson = mapper.writeValueAsString(user);
System.out.println(outJson);
//测试结果
//{"id":1,"name":"jack"}

		ObjectMapper mapper = new ObjectMapper();
		//通过该方法对mapper对象进行设置，所有序列化的对象都将按改规则进行系列化
		//Include.Include.ALWAYS 默认
		//Include.NON_DEFAULT 属性为默认值不序列化
		//Include.NON_EMPTY 属性为 空（“”）  或者为 NULL 都不序列化
		//Include.NON_NULL 属性为NULL 不序列化
		mapper.setSerializationInclusion(Include.NON_NULL);
		User user = new User(1,"",null);
		String outJson = mapper.writeValueAsString(user);
		System.out.println(outJson);

以前的版本objectMapper.configure（SerializationConfig.WRITE_NULL_PROPERTIES，FALSE）这种方式实现